Burner for pellets

Abstract

In the combustion of granular fuels in current use the ash causes problems in fusing, in connection with combustion and ash extraction and additionally in the form of fuel lost when it becomes intermingled with the ash. In the burner according to the invention the fuel is continuously fed (1) into the combustion space (9). The combustion air is fed (4) to the space (10) between the tubular parts (2,3) and from there on through the lower holes (11) in the primary air flange (7) to the perforations (12) in the grate (5) below the combustion fuel layer. The secondary air is led through the flange (7) upper part by way of the turboelements (14) and air slits (13), as a horizontally swirling air flow through the combustion chamber (9) to the furnace, where gases are burned while flowing in at a horizontal level. The flame flowing on this horizontal axis combusts any burning fuel which may have fallen to the bottom of the furnace. The ashes are extracted through the open mouth of the combustion chamber (9) to the bottom of the furnace, partly fused and partly dry. Alternatively ashes fall to the feed base located in the combustion chamber (9) from which it is extracted from the boiler.

I claim: 
     
       1. A burner for the combustion of granular fuels, comprising an inner tube, an outer tube spaced outwardly of the inner tube with the space between said tubes defining an air supply chamber, the outer end of the outer tube projecting beyond the inner end of the inner tube and the projecting end of the outer tube defining a combustion chamber, a flange connecting the outer end of the inner tube to said outer tube and separating said air supply chamber from said combustion chamber, a grate disposed within the lower end of the combustion chamber, the lower end of said flange having at least one hole providing communication between the said supply chamber and said grate, the upper portion of said grate having a plurality of openings whereby air flows upwardly from the grate into the combustion chamber, and air distribution means in the upper end of said flange for delivering air from said air supply chamber to said combustion chamber in a swirling pattern. 
     
     
       2. The burner of claim 1, wherein said air distribution means comprises a plurality of circumferentially spaced radially extending slits. 
     
     
       3. The burner of claim 2, and including turboelements disposed in said air supply chamber upstream of said slits.